Prestrain-induced bandgap tuning in 3D-printed tensegrity-inspired lattice structures

TL;DR

This study demonstrates that 3D-printed tensegrity-inspired lattice structures can have their bandgaps continuously tuned through global prestrain, offering a lightweight and elastic alternative to traditional soft-polymer metamaterials.

Contribution

It provides experimental evidence of bandgap tunability in stiff, lightweight, 3D-printed tensegrity-inspired lattices via precompression, a novel approach compared to existing soft-polymer metamaterials.

Findings

Bandgap width and location can be continuously tuned with prestrain.

Lattices exhibit nonlinear compressive response similar to tensegrity structures.

Structures remain elastic and compliant up to high precompression levels.

Abstract

In this letter, we provide experimental evidence of bandgap tunability with global prestrain in additively-manufactured tensegrity-inspired lattice structures. These lattices are extremely lightweight and designed to exhibit a nonlinear compressive response that mimics that of a tensegrity structure. We fabricate them out of a stiff polymer but, owing to their peculiar design, they are compliant and remain elastic up to high levels of precompression. In turn, unlike tunable metamaterials made of soft polymers, the response of our lattices is not dominated by damping. We perform experiments on a one-dimensional lattice subject to longitudinal wave excitation and varying levels of static longitudinal precompression, and observe continuous tuning of both the wave speed and the location and width of the lowest-frequency bandgap.